Methods and systems for determining a video player playback position

Systems and methods enable the determination of a playback position of a video player. A request is received, at a system over a network from a user device, for an item of video content. Interstitial content is received. The interstitial content is segmented into segments and the segments are encrypted. A given decryption key is associated with a respective locator, such as a URL. A playlist manifest file is generated that includes locators corresponding to segments of the requested item of video content, segments of the interstitial content, and decryption keys for respective encrypted interstitial segments. The generated playlist manifest file is transmitted to the user device. A request for a first decryption key for an encrypted first interstitial segment is received, and based on the request, a playback position of the video player is determined. A corresponding message, indicating the playback position, may be transmitted to a remote destination.